thus we are unable to set. While debugging the code, I see a mismatch between the channel native format and the existing format for videos which asterisk has. My channel native format value is 8, which I think corresponds to the case of alaw (1<<3). I do a "sip show settings" and note that: Videosupport = Yes Codec Order: g722:20, g723:30,alaw:20,ulaw:20 The audio file which I have plays, but the video file [.h263] fails to play. I am using a Bria Soft Phone, and my Linux OS is CentOs 5 configured as a Virtual Machine on Windows Vista. Welcoming your suggestions and help, Regards Sharan